In one hour, the Earth receives enough energy from the sun to meet all of mankind’s energy needs for one year. Yet the world uses little more than one percent of the sun’s energy for our electricity needs. A major obstacle to being able to tap into the full potential of solar energy is that it is intermittent—we cannot get a steady supply of solar energy because the sun doesn’t always shine.In order for renewable energy to take hold on the scale necessary to help combat climate change, an efficient and economical way to store the sun’s energy is needed for times when the sun doesn’t shine. But even when that technology becomes available, we will still need to find a way to use renewable energy to power the transportation sector, one of the largest sources of greenhouse gas emissions.